Friday, May 20, 2016

The CDC published an MMWR report, and held a press conference this morning, to explain a change in how they will report the number of pregnant women in the United States and its territories with Zika Virus infection.

Up until now, the numbers reported have only included symptomatic cases with a positive Zika test, or women who have seen an adverse pregnancy outcome and have a positive Zika test.

As studies have emerged suggesting asymptomatic carriage of the virus may also result in microcephaly, or other adverse outcomes, the CDC has been tracking those cases as well.

Starting today, those cases - as long as they have a test suggestive of a Zika virus infection - will also be included.

As a result of this broader definition, the number of pregnant women being reported (delayed by 1 week) has jumped markedly with today's update, adding 122 asymptomatic infections (+167 total).

I've included the summary, but you'll want to follow the link to read the full report.

Summary

What is already known about this topic?

Zika
virus infection during pregnancy causes microcephaly and other serious
brain abnormalities. However, the full range of outcomes of asymptomatic
and symptomatic Zika virus infection during pregnancy are not yet well
understood.

What is added by this report?

In
February 2016, CDC, in collaboration with state, local, tribal, and
territorial health departments, launched comprehensive surveillance
systems to report and actively monitor pregnancies and congenital
outcomes among symptomatic and asymptomatic women with laboratory
evidence of possible Zika virus infection. As of May 12, 2016, there
were 157 and 122 pregnant women with laboratory evidence of possible
Zika virus infection residing in U.S. states and U.S. territories,
respectively.

What are the implications for public health practice?

This
report launches the weekly reporting of pregnant women with laboratory
evidence of possible Zika virus infection in U.S. states and
territories. Monitoring all pregnant women with possible Zika virus
infection during pregnancy, whether asymptomatic or symptomatic, will
enhance understanding of possible adverse outcomes and allow better
estimates of the number of pregnancies at risk for adverse outcomes.
This information will assist health care providers who counsel pregnant
women and will facilitate planning services for affected families.